It's been known for years that the web is the distribution mechanism for the large majority of malware. While e-mail is still heavily used to lure users, the e-mail contains links to the web, not attached malware.

LinkScanner pre-screens web sites as you surf, looking for malicious activity. Competitive systems based either on reputation or asynchronous scanning simply can't keep up with the massive volume and turnover of malicious web sites. These systems, like McAfee's SiteAdvisor as well as the reputation systems built into the latest versions of everyone's browser are far from perfect, but their use provides some defense-in-depth that can't hurt.

LinkScanner isn't perfect either, but AVG claims a far higher percentage of detection than the reputation systems can possibly claim, and their argument makes sense: The people who make these malicious sites aren't especially creative and they tend to use the same techniques over and over again, especially once they get the notion that one of them is working. So while a reputation system can't keep up with thousands of new, but essentially identical malicious sites, a synchronous scanning system can detect a high percentage of them.

While it is now unbundled from their other offerings, the LinkScanner functions are also built into their more fully featured products. The separate LinkScanner can coexist with other anti-malware products.